More on Pseudohypocalcemia and Gadolinium-Enhanced MRI

To the Editor: In their letter to the editor, Doorenbos et al. (Aug. 21 issue) 1 describe seven cases of severe pseudohypocalcemia after gadolinium-enhanced magnetic resonance angiography with the use of gadodiamide. Their report represents an important warning to all physicians, especially since such laboratory interference can occur after any gadodiamide-enhanced magnetic resonance imaging (MRI) examination. Gadodiamide and gadoversetamide are the two gadolinium chelates known to interfere with the colorimetric methods of measuring serum calcium used in most hospitals. 2 – 5 However, five other gadolinium contrast agents do not show this interference: gadopentetate dimeglumine (Magnevist) and gadoteridol (ProHance), which are widely used . . .